Paracentesis stylet catheter



g- 5, 1959 M. ROBERTS 3,459,188

PARACENTESIS STYLET CATHETER Filed July 26, 1965 mrvwron Ill/UM 1708!! ATTORIVE Y United States Patent U.S. Cl. 128--347 4 Claims ABSTRACT OFTHE DISCLOSURE A catheter-stylet combination for puncturing a patientsabdominal wall for peritoneal dialysis. A rigid wire stylet fits withina bore of a laterally flexible plastic catheter and has a point on oneend protruding from the catheter and a handle engaged on the oppositeend of the catheter. The catheter has a larger internal bore than thestylets diameter and has a series of ports through the catheters wallextending from the one end to form a sieve portion permitting fluid toenter immediately after insertion while filtering out clots. The styletis substantially centered within this sieve portion by inwardlyextending flanges surrounding the ports so that the flexible tube andpiercing element combine to form a rigid combination facilitatingpenetration into a body cavity while affording substantial control as todepth of penetration.

My invention pertains to a medical paracentesis instrument for insertinga fluid conduit through a patients body wall and into a body cavity witha minimum of trauma and bleeding, such as in abdominal or thoraxparacentesis procedures.

Unlike tubes and catheters inserted through a natural body passage, suchas gastrointestinal, urethral, or rectal, a conduit entering theabdominal or thorax cavity must penetrate a body Wall. This penetrationis usually accomplished with a scalpel making a surgical incision, ahollow hypodermic needle, or a metal trocar puncturing a hole.

The surgical incision method requires a general or spinal anesthetic andis performed in an operating room. After the patient is anesthetized,the physician cuts an opening through the patients body wall with ascalpel. He then inserts the catheter through the opening and closes thewound around the catheter with a purse-string suture to prevent bleedingand fluid leakage around the catheter.

The trocar method is preferred over the incision method because itrequires only a local anesthetic at the point of puncture. This methodinvolves pushing a sharpened metal sleeve with a pointed obdurator inits bore through the patients body wall. After removal of the obdurator,a catheter is fed through the bore of the metal sleeve holding the woundopen. Once the catheter is through the body wall, the metal sleeve ispulled out and the wound sutured shut around the catheter. The trocarmethod can be used with patients who need frequent dialysis, sometimesas often as every day, but the large hole made by the metal sleeve istraumatic to the patient and takes a long time to heal.

The paracentesis instrument of my invention is functionally andphysiologically superior to existing devices,

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and provides a simple, safe and economical way of inserting a sieveportion of a thermoplastic catheter through a body wall and into a bodycavity. It punctures a hole smaller than the catheter itself and muchsmaller than the hole made by a metal trocar for inserting a similarsize conduit. Such a small hole eliminates the need for pursestringsutures to draw the wound tightly around the catheter.

My invention can perhaps be understood best by reference to thefollowing drawings, in which:

FIGURE 1 is a front elevational view of the medical instrument ready forpiercing insertion through a body wall;

FIGURE 2 is a front elevational view of the catheter of the medicalinstrument extending through a body wall with a sieve portion inside abody cavity;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1; and

FIGURE 4 is a front elevational view of a modification of the medicalinstrument which is adapted for insertion into a chest cavity.

The paracentesis instrument shown in FIGURES I, 2, and 3 is particularlysuited for insertion into an abdominal cavity for peritoneal dialysis.It includes a catheter or conduit element 1 with a wall 8 having anexternal wall surface 10 and an internal wall surface 9 defining a boreex tending between the first end 2 and second end 3 of the catheter. Anelongated piercing element 12 within the bore of catheter 1 has apointed end 5 extending from a first end 2 of catheter 1. The externalwall surface 10 adjacent the first end 2 tapers radially inwardly towardthe pointed end 5 of the elongated piercing element to provide a smoothtransition between the catheter 1 and the piercing point 5. Handle 6extends from the second end 3 of the catheter 1, and abuts this end,limiting the longitudinal movement of the catheter 1 relative to theelongated piercing element 12 upon piercing insertion into a bodycavity. The catheter 1, which is generally from 5 inches to 18 inches inlength, has sufiicient columnar rigidity to pierce the body wall alongwith the elongated piercing element 12 when force is applied to handle6.

Adjacent the first end 2 of the catheter 1 is a sieve portion 13 adaptedto go inside a body cavity 17. This sieve portion 13 has a series ofports 4 through wall 8 providing fluid passage into and out of thecatheter bore. This sieve portion has small ports 4 with diameters inthe range of 0.010 inch to 0.025 inch to filter out any clots oromentum' that may clog fluid passages through the catheter bore.

An additional feature of this invention is a puncture indicator providedby a space 7 as shown in FIGURE 3 between the elongated piercing element12 and the internal wall surface 9 of catheter 1. Upon piercing a bodyWall 16, any fluid within the body cavity will well up in space 7 and bevisible outside the body wall through transparent or translucentcatheter 1. Such an indicator feature is very useful in peritonealdialysis for showing when the peritoneum 20 has been pierced and thecatheter is in the abdominal cavity. Ports 4 have annular flanges 11surrounding them and extending inwardly from internal wall surface 9 tospacedly hold elongated piercing element 12 a distance from internalwall surface 9.

FIGURE 2 shows the catheter inserted through the wall 16 of a patientwith sieve portion 13 extending into body cavity 17. A portion of thecatheter 1 adjacent sieve portion 13 has a preformed curve. This curvedportion is straightened when elongated piercing element 12 is withincatheter 1, but snaps back to its preformed curved configuration afterremoval of the elongated piercing element 12. Such a curved portionmakes sieve portion 13 easily manipulatable in the body cavity bytwisting catheter 1. The catheter including the sieve portion, however,is laterally flexible to bend and flex as the patient moves so first end2 of catheter 1 does not jab into the patient.

The second end 3 of catheter 1 has, in the absence of elongated piercingelement 12 within the bore of catheter 1, an L-shaped tubular member 14directing fluid flow laterally from a second end of catheter 1. Previousto this L-shaped tubular means associated with the catheter, a drainagetube leading longitudinally from the second end 3 of the catheter wouldfrequently kink, thus shutting off flow to the catheter. For yearspeople have tried to overcome this problem by taping the drainage tube30 in a large loop, or constructing a makeshift splint from tonguedepressors taped to tubing leading from the catheter to a fluid supplysource. I have eliminated these problems by providing an L-shapedtubular member fixed to the second end 3 of the catheter 1. If thecatheter extends outwardly from the abdominal Wall a considerabledistance, as in a slender patient, the physician can bring the secondend 3 closer to the abdominal wall by cutting off any extra length ofthe catheter 1 and attaching L-shaped tubular member 14 to the severedend.

Referring to FIGURE 4, we turn now to a modification of my inventionwhich is particularly adapted for use in thorax paracentesis, i.e.thoracentesis. In a thoracentesis procedure, a conduit goes through thechest wall into the chest cavity, and it is highly critical that theconduit be airtight. If air leaks into th econduit he lungs cancollapse, and the patient cannot breathe. The paracentesis instrumentshown in FIGURE 4 is the same as that shown in FIGURE 1 with the addedfeature of a seal 15 at the second end of the catheter which slidinglyseals the elongated piercing element 12 to the catheter 1. Fluid entersand exits through a side channel 18 communicating with the bore of thecatheter 1 between sieve portion 13 and second end 3 of the conduitelement. Preferably, side channel 18 has a valve 26 therein to preventany air or liquid from bing unintentionally drawn into the chest cavity.A valve 19 can also be placed in the catheter 1 adjacent its second end3 so elongated piercing element 12 need not remain in seal 15 afterinsertion of the catheter through body wall 16. Valve 19 would stop anyleakage through the punctured hole in seal 15. Valves 26 and 19 may becombined in a single valve element at the fork of catheter 1 and sidechannel 18.

The tubular conduit element or catheter 1 is laterally flexible formanipulation inside a body cavity without injuring the patient whileelongated piercing elemnt 12 is much stiffer and supports the catheterupon piercing a body wall 16. Tubular cathter 1 can be of athermoplastic material such as nylon, polypropylene, polyethylene, orpolyvinyl chloride. Elongated piercing element 12 may be solid and ofmetal or of a stiff thermoplastic material such as nylon or Delrin.

To illustrate how the medical instrument of my invention operates, Iwill briefly describe a peritoneal dialysis procedure. With theelongated piercing element 12 in the bore of catheter 1, as shown inFIGURE 1, a physician pushes the pointed end through the locallyanesthetized abdominal wall 16. On piercing the peritoneum layer 20along the inner surface of the abdominal wall 16, liquid enters space 7through ports 4 and wells up within catheter 1. The physician can thenwithdraw the pointed end 5 back into catheter 1 slightly so as not toinjure any of the organs in the abdominal cavity during deeperinsertion. After completely inserting the sieve portion 13 of thecatheter 1, and removing elongated piercing element 12, the physiciancuts off an excess length of the catheter 1 extending outwardly from theabdominal wall 16. Next he attaches L-shaped tubular means 14 to thesevered end of catheter 1. A source of dialyzing solution is thenconncted through a tube 30 to L-shaped tubular means 14, and peritonealdialysis begins.

For illustrative purposes I have used specific examples to describe myinvention. However, it is understood that persons skilled in the art canmake certain modifications to these examples without departing from thespirit and scope of this invention.

I claim:

1. A paracentesis instrument for puncturing a patients body wall toprovide a fluid channel communicating with a body cavity, whichinstrument comprises:

(a) a generally constant diameter, laterally flexible, thermoplastictubular conduit element having a wall surrounding a bore extendingbetween first and second ends of the conduit element, said wall having agenerally cylindrical internal wall surface and a generally cylindricalexternal wall surface;

(b) said conduit element having a sieve portion substantiallyimmediately adjacent its first end with a series of ports through itswall to provide fluid flow into and out of said bore through said ports;

(c) a removable, straight and rigid, elongated piercing element withinthe bore of the conduit element, one end of the piercing element beingpointed and extending slightly beyond the first end of the conduitelement, the opposite end of the piercing element extending from thesecond end of the conduit element, said piercing element having a singlesolid homogeneous rod-like element having a substantially uniformcross-section and extending between opposite ends of the conduit elementand engageable with portions of the conduits internal wall surfacebetween the sieve portion and the second end of the conduit element;

((1) handle means on one end of the piercing element,

which handle means abuts the conduit elements second end and extendsboth longitudinally and laterally beyond the conduits second end, therigid piercing elements length between its handle and its pointed endbeing approximately the same as the conduit elements length so the firstend of the conduit element is very near the pointed end of the piercingelement when the conduit element has its second end abutting said handlemeans;

(e) which conduit element has a larger internal diameter than thepiercing elements external diameter to provide an axially extendingspace therebetween extending the length of said rod; and

(f) which conduit element has flanges surrounding said ports, whichflanges extend inwardly from the internal wall surface terminating inspaced relation from the outer surface of said piercing element tomaintain the elongated piercing element spaced from the internal wallsurface of the conduit in the area of the sieve portion for permittingfree movement of said piercing element in said conduit element, andpermitting free movement between the inner surface of said conduit andthe outer surface of said piercing element while the piercing andconduit elements are embedded in a body cavity.

2. A paracentesis instrument as set forth in claim 1 wherein the conduithas a preformed curve straightened by said elongated piercing element,said conduit element returning to a curved configuration upon removal ofthe elongated piercing element.

3. A paracentesis instrument as set forth in claim 1 wherein theelongated piercing element is slidably sealed to the conduit element bya resilient member near the conduit elements second end, and wherein aside channel communicates with the bore of the conduit element betweenthe second end and said ports.

3,459,188 5 6 4. A paracentesis instrument as set forth in claim 3FOREIGN PATENTS wherein the side channel has a valve. 1 006 845 1/1952France References Cited OTHER REFERENCES UNITED STATES PATENTS 5 Lancet,October 1964, pp. 792-94. 2,458,305 1/1949 Saunders 128-348 Lancet, May15, 1965, pp. 1047-49. 2,836,180 5/1958 Strauss 12s -214.4 3,030,9534/1962 Koehn 12s- 214.4 DALTON TRULUCK, Primary Examiner 3,064,65311/1962 Coanda 128-348 3,312,220 4/1967 Eisenberg 128214.4 10

3,313,299 4/1967 Spademan 12s-214.4 123-214, 221

